Before fatal leak, DuPont scrambled to fix phosgene problems

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Read the reportCHARLESTON, W.Va. -- In the hours before a fatal Jan. 23 phosgene leak at the DuPont Co. plant in Belle, company officials were scrambling to fix problems with the phosgene tanks and hoses involved in the accident, according to a newly released DuPont investigation report.The day before the leak, DuPont was having trouble with pressure from one of two phosgene cylinders that supplies the chemical building block to a pesticide production unit, according to the report.DuPont replaced the supply hose on one of the two tanks when it discovered damage that had been covered up by a manufacturer's label, but apparently missed similar damage on the other tank's hose, which eventually leaked, the report said.

Shortly after 2 p.m. on Jan. 23, longtime plant worker Danny Fish was sprayed with phosgene as he conducted a safety check inside a shed where DuPont keeps the phosgene supply cylinders.DuPont initially said Fish was transported to a local hospital "for treatment and observation as part of the standard protocol for exposure to this material." Fish died the following day.Phosgene is a valuable building block for making other chemicals and DuPont uses it to produce various crop protection chemicals. But, it is also extremely toxic. It was used as a chemical weapon in World War I, and is considered dangerous even in very tiny levels.Previously, the U.S. Chemical Safety Board has said the braided-wire phosgene hose that leaked at DuPont showed signs of serious wear, and the federal Environmental Protection Agency reported that it was long overdue to be replaced.
But the new DuPont report provides the most details to date of what happened leading up to the fatal leak that has prompted numerous federal investigations and led Sen. Robert C. Byrd to say he was "alarmed" by safety lapses at the Belle plant.Last week, DuPont provided a copy of its internal report to various regulatory agencies. Initially, the company insisted that 24 entire pages of the 31-page document contained "confidential business information" that could not be released.The Gazette-Mail asked the state Department of Environmental Protection for a copy of the entire report. DEP officials reviewed it, and questioned DuPont's broad claim for confidentiality. Earlier this week, DuPont withdrew most of its claims for confidentiality and DEP provided a copy of the complete report.According to the report, DuPont had begun mixing a batch of chemicals at about 10:45 a.m. the day before the leak. But the flow of phosgene from one of the two tanks -- the one referred to as the "hillside" cylinder -- was "insufficient."

Plant operators began "switching between" the hillside cylinder and a second tank known as the "riverside cylinder," the DuPont report said. "Sufficient flow was obtained from the riverside cylinder, but switching the cylinders did not resolve the low flow issue on the hillside cylinder," the report said.According to the report, plant operators thought, "the flow issue was due to a problem with the valve on the hillside phosgene hose assembly" because the valve would not open as much as it usually did."The operators left the manual valves from the riverside cylinder to the process open after the batch was complete," the report said. "The liquid phosgene was not evacuated from the hose and valve assembly."

That evening, DuPont decided to replace the hillside cylinder's hose assembly the next morning before starting another batch of chemicals.Workers cleared phosgene from the hillside cylinder's hose assembly, and at the same time closed the valves between the riverside cylinder and the pesticide unit, the report said.At about 9:15 a.m. on Jan. 23, a mechanic replaced the hillside cylinder hose and valve assembly. The next batch of chemicals was started at about 9:55 a.m. using the hillside cylinder.Workers put the hillside cylinder's old hose into a bucket of water to decontaminate it, the report said. Later, they noticed "there was a section of the wire over-braid approximately one-half inch long that was missing around the full circumference of the hose."The missing over-braid on the hillside hose had not been apparent to the operators or mechanics when they removed it from service because it is believed that a manufacturer's tag was tightly wrapped around the hose and covered the area of missing over-braid," the DuPont report said. "The manufacturer's tag was no longer present when the hillside hose was removed from the bucket of water."After the missing over-braid was observed on the hillside hose, the operators visually checked the riverside hose for similar damage while it was in service," the report said. "A manufacturer's tag was wrapped around the riverside hose, and no deterioration of the wire over-braid was apparent on the riverside hose."

At about 2 p.m. that afternoon, Fish went into the phosgene shed to check the hillside phosgene cylinder weight on a scale."While the operator was checking the hillside phosgene cylinder weight on the scale, he heard a 'pop' and was sprayed with phosgene from the riverside hose, believed to be in the form of a fine mist/vapor," the DuPont report said. "The operator passed away the following day."Reach Ken Ward Jr. at kward@wvgazette.com or 304-348-1702.